The amount of democracy-destroying money that manages to make its way into the sleazy environs of what is now known as Boehner Land has increased to a staggering degree.
I'm not sure this is an example of "democracy-destroying money." If my memory serves me correctly men that would be rather more popular with the Bob Herbert's of the world were also well known for their influence peddling, Lyndon Johnson comes to mind as having a reputation for this. The form of this influence peddling was likely different, decades separate them, but I doubt the dynamics of influence peddling have changed that much.
This isn't to say that I have no problems with money and politics. But as much as it angers voters this back room (or in this case front foyer) influence peddling hasn't ever really been in any way "democracy-destroying," its simply the slightly sordid way that things actually get done. The proper check on this is that if it begins to thwart the public will and to harm the country angry voters can throw the bums out.
Money becomes "democracy-destroying" when it disrupts the process of the public learning of how their officials are acting to provide rents to the politically connected and then throwing the bums out. Its not the back room trading of money and influence that is "democracy-destroying" but the ability of money and influence to shape public opinion and prevent less wealthy or connected voices from being heard that is potentially "democracy-destroying."